Receiving apparatus for wave-signaling



R. V. L. HARTLEY. RECEIVING APPARATUS FOR WAVE SIGNALING.

APPLICATION FILED SEPT-30,1915.

1,387,262. I Patented Au 9,1921- UNITED STATES PATENT OFFICE.

RALPH 'VLL. HARTLEY, OF EAST ORANGE, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS, TO WESTERN ELECTRIC COMTANY, INCORPORATED, A CORPO- RATION OF NEW YORK.

RECEIVING APPARATUS FOR WAVE-SIGNALING.

Specification of Letters Patent.

Application filed September 30, 1915. Serial No. 53,430.

'To all whom it may concern:

Be it known that I, RALPH VINTON LYON HARTLEY, a citizen of the United States, residing at East Oran e, in the county of Essex and State of ew Jersey, havefinvented certain new and useful Improvements in Receiving Apparatus for Wave-Signaling, of which the following is a full, clear, concise, and exact descriptlon.

This invention relates to circuits to be used for thereception of high frequency signaling. waves, and more particularly to the reception of sustained waves such as are used in wireless telegraphy, where use is made of the heterodyne .principle for reception, or in wireless telephony. Its purpose is to provide a circuit which is adapted,

y a ready change, to receive telephonic or telegraphic messages in a usual way, or to receive telegraphic messages by the heterodyne principle from stations using continuous waves, that is, by the generation at the receiving station of oscillations of a frequency differing slightly from the signaling requency and combiningthem with the received waves to foi'm beats of a definite frequency.

Its purpose. is accomplished by making use of the fact that a,thermionic amplifier of the audion type can be arranged in a circuit to act as a generator of high-frequency oscillations of any desired, frequency.

The invention consists in so arranging a thermionic amplifier in association with an ordinary telephone receiving set, equipped with a suitable detector, that it may act in the circuit as a local generator of high-frequency oscillations to produce beats, or may be cut out of the circuit.

The invention will'be better understood by reference to the accompanying drawing in which the 'figure shows. one form of cir-- cuit arrangement suitable for the purpose. In the figure, 10 represents an elevated conductor or other suitable receiving system for electromagnetic waves, this elevated conductor being connected through an inductance ll, to the earth 14. Inductively connected to the antenna is the receiving resonant circuit with inductance 12 and con-- denser 13. Connected to this receiving ciring device. In this case there is shown connected around the condenser 13 a voltageoperated detector consisting of a thermionic detector of the audion type. This detector includes the usual heated filament 15, grid 16 and plate 17. The input circuit of said detector is connected to the terminals of the condenser 13, having in circuit the condenser 20 and connected across the input circuit the high resistance 21. In the output circuit is the usual battery 22 and translatin device 23, which may be-of-any suitable orm, but is Preferably a telephone receiver. The system, asso far described, is adapted to receive telephonic messages or telegraphic messages sent in any usual way, such as in groups of trains of waves.

From some transmitting stations it is customary in telegraphing to send out Waves of a constant amplitude which are broken up into groups for signaling purposes, or which have some characteristic, such as wave length, modified in accordance with signals to be transmitted. One common method for receiving such signals is based on the heterodyne prlnciple which consists in generating at the receiving station high-frequency oscillations of a frequency diifering slightly from the signaling frequency. The combination of these two oscillations of slightly difi'ering frequency results in beats whose frequencyis equal to the difference in frequency of the two oscillations which are combined. By suitable detecting devices, the resulting oscillation gives a note in a suitable receiver whose pitch is equal to the the switch 42 to some intermediate point of the inductance, this point being preferably ad'ustable as shown.

Vhen the switches 40, 41 and 42 are open, the receiving system operates in the usual way to receive telegraphic or telephonic Patented Aug. 9, 1921.

messages. When the switches are closed, the point of contact of the key 42 is ad usted so that the thermionic amplifier, in connection with the circuit 12, 13, generates oscillations of a frequency slightly different from the signaling frequency. In this case the coupling between the output and the input-01r- -cuits of the amplifier is such that the system is in the sensitive near-singing condition for the frequency of the signals to be received and such as not to permit excessively large currents to .be generated. The received signals will, therefore, be strongly amplified in the oscillatory circuit, and combined with the locally generated oscillations, will roduce beats. The effect of these upon the etecting and translating set will be to,

produce a signal in the translatingdevice which has a pitch equal to the beat frequency. The beat frequency may be varied by slightly varying the frequency of the osoillatory circuit if desired, rather than adjusting the point of contact of the key 42' or the adjustment may be made in any other known manner.

What is claimed is:

1. In a radio receiving system, a receiving antenna, a detector and a translating device, a circuit tuned to the signaling frequency and connected between said antenna and said detector, means conductively connected to said tuned circuit to cause the production of high frequency oscillations of a frequency different from the signaling frequency for heterodyne'reception, and switching means for disconnecting said conductlvely connected means to render said detector and translating device operative to receive telephonic messages.

2. In a radio receivmg system, a receiving antenna, a detector and a translating device, a circuit tuned to the signaling frequency .for transmitting received energy from said antenna to said detector and translating device, means forming with said tuned circuit a generating system for oscillations differing from the signaling frequency to enable said detector and translating device to receive signals by heterodyne effect, and switching means for disassociating said means from said tuned circuit to render said detector and translating device operative to!" receive telephonic messages. I,

3. In a radio receiving system, a receiving antenna, a detector and a translator, a circuit tuned to the signaling frequency for transmitting received energy from said antenna to said detector and translator, a thermionic amplifier connected to said circuit and forming with said circuita generating system for oscillations of a frequency differing from the signalin frequency for rendering said detector an translator operative as a heterodyne receiver, and switching means for disconnecting said amplifier from said tuned circuit to render said detector and translator operative to receive telephonic messages.

4. In a radio receiving system, a receiving antenna a circuit comprising a condenser and inductance tuned to the signaling frequency and inductively connected to the antenna; a detector and translating device associated with said circuit and adapted to receive telephonic messages; a thermionic amplifier of the audion type, means for conductively connecting the terminals of said amplifier to the tuned circuit to cause the production of high-frequency oscillations of a frequency differing from the signaling frequency, whereby when" the terminals are so connected the system is rendered operative as a heterodyne receiver and when they are disconnected is adapted to receive telephonic messa es.

5. n a radio receiving system, a'receiving antenna, a circuit tuned to signaling frequency inductively coupled to said antenna, a detector havingits input circuit connected to said tuned circuit, a translating device in the output circuit of said detector, a thermionic amplifier of the audion type,m'eans for conductively connecting its terminals to the tuned circuit to cause the production of high frequency oscillations of a frequency differ,- ing from the signaling frequency, whereby when connected the system is rendered operative as a heterodyne ,receiver and when disconnepted is adapted to receive telephonic messages.

6. In a radio receiving system, a receiving antenna, a circuit comprising a condenser and an inductance tuned to the signaling frequencyand inductively connected to the antenna, a detector and translating device 105 associated with said circuit and adapted to receive telephonic messages, a thermionic amplifier of'the audion type, means for connecting the grid element of said amplifier to one end of the inductance in said tuned circuit, 110, means for connecting the plate/electrode of said amplifier to the other end of said inductance, and means for adjustably connecting the filament of said amplifier to an intermediate pointof said inductance whereby when so connected the system is caused to produce high frequency oscillations of a frequency difi'eri from the signal frequency and is rendereti bperative as a heterodyne recelver.

7. In combination, a receiving conductor, a tuned circuit electrically connected to said conductor, a detector connected to said circuit, a signal translating device connected to said detector, local means for generating oscillations the frequency determining element of which is .said tuned circuit, said means including an energy transfer circuit and a switch for opening said energy transfer circuit to render said means inoperative 13( to produce oscillations whereby in one position of said switch heterodyne detection may be effected and in another position thereof simple detection is accomplished.

8. In a signaling system, a circuit tuned to the frequency of incoming signal oscillations, a detector and a receiver, associated therewith, an electron discharge device, and means for connecting said electron discharge device to said tuned circuit, said device and said circuit of themselves constituting a generator of oscillations of frequency differing from that of said incoming oscillations.

9. In a heterodyne signaling system, a circuit tuned to. the frequency of incoming signal waves, a vacuum tube device and means included in its input and output circuits to connect its input and output circuits with said tuned circuit to cause said device to produce in said tuned circuit oscillations of frequency different from that of the incoming signal waves.

.10. In combination, a receiving conductor, a tuned oscillation circuit associated therewith, an inductance in said tuned circuit, a vacuum tube oscillator having input and output circuits, each including at least a portion of said inductance for producing oscillations having a frequency different from thatof the natural frequency of said circuit, and means for varying the amount" of said inductancein each circuit.

11. In a receiving system, an antenna and a frequency changing detector, a circuit containing inductance and capacity andtuned to the frequency of the incoming waves for conveying said waves from said antenna to said detector, an amplifier having electrodes and a control element, and means for 'connecting said electrodes and control element to different points respectively of said tuned circuit for causing said amplifier to generate oscillations.

12. In a receiving system, an antenna and .a frequency changing detector, a circuit containing inductance and capacity and tuned to the frequency of the incoming waves for conveying said waves from said antenna to said detector, an amplifier having electrodes and a control element, and means for connecting said electrodes and control element directly to said tuned circuit for causing said amplifier to enerate oscillations for said detector difi'ering slightly in frequency. from the incoming waves.

13. A circuit including a plurality of discharge devices, and connections *fontransferring energy from the output circuit of one deviceto the input circuit of the next succeed ng device, and means for severmg said one device from said circuit while leaving the circuit of the next succeeding device intact.

14. A translating circuit-including a receiver and two discharge devices, switching means arranged when thrown one way to sever the first device from the circuit and to transmit received energy to the second device, and when thrown the other way to include said first device in said circuit and transmit the output energy of said device to the input circuit of said second device.

15. In a receiving circuit, a receiver and a. pair of discharge devices, the output of one device feeding into the input of the other device, and switching means for severing said one device from. the circuit and transmitting the energy received directly to the other device and thence to said receiver, or for including said one device in the circuit and transmitting energy through both of said devices in succession to said receiver.

16. In combination, a plurality of vacuum tubes arranged in tandem each, comprising a cathode, a control electrode and an anode, a source of variable electromotive force, means including afixed connection between said source and an input electrode of one of said tubes for impressing currents from said-source upon said tubes, and means for effectively cutting out one of said tubes while permanently maintaining said fixed connection. 17 In combination, a plurality of vacuum tubes arranged in tandem each comprising a cathode, a control electrode and an anodfi, J

means including a fixedconnection between said source and the cathode-of one of said tubes for impressing currents from said source upon said tubes, and means for effectively cutting out one of said tubes while permanently maintaining said fixed connection.

18. In combination, an incoming line, an outgoing line, a plurality of vacuum tubes connected in tandem therebetween, each vacuum tube having an input electrode and an output electrode, and means for connecting one of said lines to each" of a plurality of one set of said electrodes, said means including switching means for severing the connection of saidlast mentioned line to one of said electrodes to reduce the number of tubes efiectively connected in tandem between said lines.

In witness whereof, I hereunto subscribe my name this 20th day of September, A. D. 1915.

RALPH V. L. HARTLEY. 

